In recent years, there has been suggested an image forming system in which an image forming apparatus is combined with various peripheral devices. One example is an image forming system in which the image forming apparatus is combined with an optional peripheral device on user's demand depending on the circumstances under which the system is used.
For example, by adding a sheet (recording material) feeding device to an image forming apparatus as a peripheral device, it is possible to provide an image forming system capable of easy mass printing. Another example may be an image forming apparatus capable of two-sides printing (surface and rear face of the sheet) in view of resource saving or efficiency of work.
Such combination with a peripheral device improves efficiency of image forming, and therefore the demand of these image forming systems is increasing.
Further, consumption of sheets used for image forming apparatuses or image forming systems is now much larger than ever, and a sheet feeding device (large capacity recording material feeding device), which stores a large amount of sheets and supplies the sheets to an image forming apparatus, is required to have a lot larger capacity.
Japanese unexamined patent publication No. Tokukai 2000-318848 (published on Nov. 21, 2000) discloses an example of sheet feeding device for feeding sheets to an image forming apparatus.
This sheet feeding device is installed on an image forming apparatus by being lifted to be connected to a positioning member of the image forming apparatus.
After combined with the main body of the image forming apparatus, the sheet feeding device is held with the bottom caster untouched with the floor. In this way, the sheet feeding device and the image forming apparatus are combined at a proper position, thus ensuring sheet feeding performance from the sheet feeding device to the image forming apparatus.
More specifically, since positioning of two devices is performed with the sheet feeding device untouched with the floor, the sheet feeding device can be relatively easily brought to a predetermined position, allowing the sheet exit of the sheet feeding device to be met the sheet inlet of the image forming apparatus.
If the positioning of the two devices is performed with the sheet feeding device touched with the floor, inclination and/or irregularities of the floor makes the positioning difficult. Further, even if the positioning succeeded, deformation of the floor with time or the like may cause displacement of combined part of the sheet feeding device and the image forming apparatus. This causes a decrease in sheet transfer efficiency.
However, in the arrangement disclosed in the foregoing publication, the body of the sheet feeding device is not in contact with the floor when combined with the image forming apparatus, and therefore sheet supply can be performed with the both devices combined at a right position.
However, in the arrangement of the foregoing publication, the sheet feeding device has to be lifted completely away from the floor to be combined with the image forming apparatus. This is a certain burden in installation.
More specifically, in the arrangement of the foregoing publication, the sheet feeding device needs to be lifted completely away from the floor when combined with the image forming apparatus, so as to be met the positioning member of the image forming apparatus. However, when the sheet feeding device is large and/or heavy, there is a serious difficulty in lifting or installation of the sheet feeding device.
Further, in the arrangement of the foregoing publication, the positioning member for enabling proper combination of the sheet feeding device and the image forming apparatus at a certain position is provided at the bottom of the sheet feeding device. Therefore, it is difficult to confirm the positioning member at the bottom of the device by user's eyes, making combining the sheet feeding device into the image forming apparatus difficult.
The present invention is made in view of the foregoing conventional problems, and an object is to provide a sheet feeding device allowing easy installation into an image forming apparatus; an image forming apparatus; and an image forming system. The present invention further relates to a method of installing a peripheral device, and a method of easily connecting devices.